This invention relates to a portable shielding and shoring device for securing the sidewalls of an excavation. More specifically, the instant invention relates to a trench shielding and shoring system having panel ends slideably connectable with panel connectors, thereby reducing the need for pins, bolts, clamps or other connection methods during assembly.
Trench excavation is recognized by the Occupational Safety and Health Administration (xe2x80x9cOSHAxe2x80x9d) as being an extremely hazardous construction operation. Due to unstable soil conditions, improper sloping of an excavation and/or other unaccounted for occurrences, landslides and cave-ins ensue. These natural occurrences have been known to destroy equipment, postpone job completion and, most seriously, injure or kill the workers inside the excavation. Therefore, xe2x80x9cshieldingxe2x80x9d and/or xe2x80x9cshoringxe2x80x9d of trench faces is required by OSHA. Trench xe2x80x9cshieldingxe2x80x9d is known by those skilled in the art to protect workers from cave-ins and/or landslides, but allows for normal shifts and fissures of the trench face. Trench xe2x80x9cshoring,xe2x80x9d on the other hand, is used to prevent any movement of the trench face when excavating near foundations, roadways or existing underground utilities, so as not to damage the same. Contractors who do not comply with OSHA""s regulations on trench safety procedures are taking a grave risk.
Known shielding and shoring devices are constructed with panels having a vertical face made of either wood or metal using various heights and widths and being held in spaced apart relationship with support bars, commonly referred to in the industry as spreaders or struts. Typically, shielding and/or shoring devices are assembled above ground at the job site by workers. These devices are laboriously assembled by first fastening each panel end to individual panel connectors through the use of a plurality of pins or clamps. Lateral support bars are then connected between each pair of oppositely disposed panel connectors to complete the device. Once assembled, the shielding and/or shoring device is placed in the excavated trench.
Examples of shoring or shielding devices include U.S. Pat. No. 4,114,383 to Nieber, which describes a portal frame for a trench box structure, showing vertical structural columns in the form of H-shaped beams being connected to panels and then bolted. Another shoring device is disclosed in U.S. Pat. No. 5,232,312 to Jennings et al., showing horizontal whalers being connected directly to the shielding panels by multiple fasteners. Finally, a trench box device described in U.S. Pat. No. 4,993,880 to Collins shows upper and lower strut connecters being bolted or welded to end-posts for connecting the panels to the struts. The end posts are permanently attached by weld to the face of the panel.
The problem with the aforementioned shoring and/or shielding devices is that multiple fasteners must be used during assembly. This means that it takes a substantial amount of time to attach the panel ends and panel connectors together using pins or clamps. Furthermore, because of their small size, fasteners are often lost or misplaced in a busy construction environment. Assembling a typical shoring and/or shielding device is therefore overly time consuming and burdensome for an already busy contractor. In fact, some deaths resulting from cave-in accidents would have been prevented if a contractor had taken the necessary time to assemble a trench box properly. In an effort to save time and meet completion deadlines, some contractors may even try to cut comers by neglecting to assemble and place a shielding device in the trench, having workers do their job in a trench that is not properly secured.
For the foregoing reasons, there is a need for a shoring and/or shielding device which is quick and easy to assemble, use, disassemble and store, without sacrificing strength and reliability.
The present invention is directed to a portable shielding and shoring device for securing the sidewalls of an earthen excavation. More specifically, this invention satisfies the need for a shielding and shoring device that is safe and durable, as well as easy to assemble, use and disassemble. For purposes of this description, we will refer to the instant invention as a shoring device, although it is applicable for both shielding and shoring purposes.
The instant invention comprises a pair of walls comprising at least one panel mutually facing each other and held in spaced apart relationship by at least one support bar on each side. An embodiment of the invention may comprise at least three planks to make a panel. Attached at opposite ends of each panel are permanently attached vertical supports, which are arranged to pair in a substantially perpendicular coupling relationship with the corresponding vertical supports of the opposite panel. Each vertical support traverses along the height of the panel and has a first engaging link. Panel connectors having a second engaging link are slideably correctable with each panel end by simply interlocking the corresponding first engaging link of the corresponding vertical support with the second engaging link of the panel connector. The second engaging link may be a male connecting extension designed to have a substantially rounded cross-section with a lateral extension attached to the inside channel of a connector body, a substantially T-shaped cross-section or a substantially mushroom-shaped cross-section. Accordingly, the first engaging link may be a female connection bracket. The support bar attaches between two panel connectors on paired panels by support bar adaptors which are substantially aligned. Further, each panel connector has a bottom stop plate and a top panel lock to vertically secure the connected panel thereto.
There are several advantages of the instant invention over the prior devices. For example, because of the sliding connection between the panel connectors and the vertical support members of the panels, the shoring device is easy for contractors to assemble, use and disassemble without sacrificing strength and reliability, and the height of the wall may be easily changed by slideably connecting and stacking additional panels, or removing the same, in corresponding panel connectors.
Accordingly, it is an objective of the present invention to provide a device that is fast to assemble, disassemble and store in a busy construction environment.
It is yet another of the present invention to provide a device that does not require the use of several fasteners, such as pins or clamps, to connect panel connectors with vertical supports.
Still another object of the present invention is to provide a device that meets OSHA safety requirements for trench excavation work.
Further, another object of the present invention is to provide a device that requires fewer small parts, which facilitates easy assembly at the construction site.
Many other objects and features of the present invention will be obvious to those having skill in the art upon contemplation of the disclosure herein in connection with the accompanying drawings.